Childhood overweight and obesity is at epidemic proportions affecting over 30% of children and adolescents with pathologic effects on the central and autonomic nervous systems. Childhood obesity is associated with risk factors into adulthood for cardiovascular disease (CVD), including elevated blood pressure, dyslipidemia, metabolic syndrome, and type 2 diabetes mellitus. Despite the potential benefit for cardiovascular health, there remains significant heterogeneity in who adopts behavior changes in the context of a weight management trial. Neurocognitive functioning-cognitive function and functional and structural brain morphology-is a key factor related to weight loss outcomes. Over a 5 year period, 176 youth who are obese with no co-occurring medical conditions and 88 youth who are normal weight will be recruited from The University of Pittsburgh to participate in a best practice, 6-month, evidence based intervention-Healthy Habits 4 Life. The overarching goals of this study are to: (1) Document that adolescents with uncomplicated obesity exhibit cognitive, task- evoked functional brain activity, and gray and white matter structural deficits in frontal-striatal systems supporting inhibition and reward compared to a control group; (2) Test the relationship between baseline cognitive function and weight loss during an intervention; and (3) Develop group-based trajectories of brain function from baseline to 6- and 12-months for youth who underwent the weight loss intervention to delineate brain profiles and how these profiles affect weight management outcomes. Such information about the impact of cognitive function on weight management outcomes could be a significant step in tailoring interventions (e.g., therapeutic targets, fMRI biofeedback, pharmacotherapy) and improving care for childhood obesity and cardiovascular disease.